No, we don't need "Part 2" continuations any more. The scenario Amos suggests is not likely to cause a huge problem, so I think we're better off not starting continuation threads.
If I see short continuation threads, I will generally delete them and move their messages into the earlier thread. I won't bother if the continuation thread is long.
Now, I realize that there may be times when a "part 2" is reasonable, but I think that should be the exception, not the rule.
-Joe Offer-